A Problem of Classification: 2 Cases of Epstein-Barr Virus + Primary Cutaneous Plasmacytoma Arising in Immunocompetent Elderly Patients.

ABSTRACT: Primary extramedullary plasmacytoma is rare monoclonal proliferation of plasma cells, which arise in various nonosseous anatomic locations without detectable underlying systemic disease. Historically, cutaneous infiltrates rich in mature neoplastic plasma cells have fallen into one of the following categories, plasmacytoma, lymphoplasmacytic lymphoma, and marginal zone lymphoma, which included immunocytoma. Since 2005, each of these was subsumed under the marginal zone lymphoma umbrella, largely on the basis of acknowledged diagnostic difficulties in some of these cases. We describe 2 cases in which the cutaneous infiltrates consisted of a pure population of light chain-restricted mature plasma cells in the absence of any other evidence for a marginal zone proliferation, or evidence of extracutaneous involvement, including a paraprotein. We propose that primary cutaneous plasmacytoma is the accurate diagnosis and is consistent with wider nomenclature. The unusual observation of widespread Epstein-Barr virus expression in both tumors is also discussed.

EBV-Positive Plasmacytomas Involving a Nasopharyngeal Angiofibroma in an Adolescent.

We report comprehensive characterization of an unusual collision tumor comprising extramedullary plasmacytomas and nasopharyngeal angiofibroma in a pediatric patient, which has yet to be reported. Histologically, the nasopharyngeal angiofibroma showed typical morphology with a diffuse, dense plasmacytic infiltrate in the stroma. The neoplastic plasma cells showed a spectrum of well-differentiated, plasmablastic, and anaplastic morphology, Epstein-Barr virus encoded RNA (EBER) positivity, and aberrant immunophenotype. Fluorescence in situ hybridization using a plasma cell myeloma targeted panel detected gains of 1q21.3 (CKS1B, x3), 3q27 (BCL6, x4), and 11q22.3 (ATM, x3), but no rearrangement of ALK and MYC. A 50-gene next generation sequencing lymphoma panel failed to detect any pathogenic mutation. Plasmacytoma with EBER positivity and plasmablastic morphology must be distinguished from plasmablastic lymphoma due to different clinical management and prognosis. This case highlights the importance of a thorough pathological evaluation of a mass lesion with synchronous neoplastic processes.

Extramedullary plasmacytoma of the nasal cavity and ethmoidal sinus in human immunodeficiency virus-positive patient.

Extramedullary plasmacytoma (EMP) occurring in the nose and paranasal sinus regions are rare with a male preponderance in the fifth and seventh decades of life. We report a case of EMP of the nasal cavity and ethmoid sinus in a 28-year-old female with human immunodeficiency virus infection.

Epstein - Barr virus association with plasma cell neoplasms.

AIMS: Epstein-Barr virus (EBV) expression has been reported in several hematopoietic and non-hematopoietic disorders but its expression in plasma cell neoplasms has been largely limited to immunodeficiency-related cases such as in the setting of post-organ transplantation or human immunodeficiency virus (HIV) infection. The aim of this study is to evaluate the association of EBV with plasma cell neoplasms, mainly in immunocompetent patients. METHODS AND RESULTS: We retrospectively studied 147 cases of patients with different plasma cell neoplasms (109 plasma cell myelomas, 22 plasmacytomas, and 16 monoclonal gammopathy cases). Six patients were immunocompromised. EBV was positive in 6 cases; 3 immunocompromised (2 patients with HIV infection and 1 patient was post-renal transplant) and 3 immunocompetent patients with plasmacytoma and variable plasmablastic features. CONCLUSIONS: Our data shows that EBV was negative in all plasma cell myeloma cases in immunocompetent patients and has an overall low association with the different plasma cell neoplasms in the immunocompetent setting. When expressed, it is usually associated with variable plasmablastic features.

Kaposi's Sarcoma-Associated Herpesvirus Latency Locus Renders B Cells Hyperresponsive to Secondary Infections.

Kaposi's sarcoma-associated herpesvirus (KSHV) induces B cell hyperplasia and neoplasia, such as multicentric Castleman's disease (MCD) and primary effusion lymphoma (PEL). To explore KSHV-induced B cell reprogramming in vivo, we expressed the KSHV latency locus, inclusive of all viral microRNAs (miRNAs), in B cells of transgenic mice in the absence of the inhibitory FcγRIIB receptor. The BALB/c strain was chosen as this is the preferred model to study B cell differentiation. The mice developed hyperglobulinemia, plasmacytosis, and B lymphoid hyperplasia. This phenotype was ameliorated by everolimus, which is a rapamycin derivative used for the treatment of mantle cell lymphoma. KSHV latency mice exhibited hyperresponsiveness to the T-dependent (TD) antigen mimic anti-CD40 and increased incidence of pristane-induced inflammation. Lastly, the adaptive immunity against a secondary infection with Zika virus (ZIKV) was markedly enhanced. These phenotypes are consistent with KSHV lowering the activation threshold of latently infected B cells, which may be beneficial in areas of endemicity, where KSHV is acquired in childhood and infections are common.IMPORTANCE Kaposi's sarcoma-associated herpesvirus (KSHV) establishes latency in B cells and is stringently linked to primary effusion lymphoma (PEL) and the premalignant B cell hyperplasia multicentric Castleman's disease (MCD). To investigate potential genetic background effects, we expressed the KSHV miRNAs in BALB/c transgenic mice. BALB/c mice are the preferred strain for B cell hybridoma development because of their propensity to develop predictable B cell responses to antigen. The BALB/c latency mice exhibited a higher incidence of B cell hyperplasia as well as sustained hyperglobulinemia. The development of neutralizing antibodies against ZIKV was augmented in BALB/c latency mice. Hyperglobulinemia was dampened by everolimus, a derivative of rapamycin, suggesting a role for mTOR inhibitors in managing immune activation, which is hallmark of KSHV infection as well as HIV infection.

Solitary plasmacytoma associated with Epstein-Barr virus: a clinicopathologic, cytogenetic study and literature review.

Solitary plasmacytoma (SP) is an uncommon, indolent tumor of plasma cell neoplasms that presents as a mass lesion in extramedullary sites. Evidence of Epstein-Barr virus (EBV) infection is frequently associated with various lymphatic and hematopoietic malignancies but is relatively rare in SP. Moreover, it is essential to distinguish EBV-positive plasmacytoma from plasmablastic lymphoma. In this study, we found 4 EBV-encoded RNA (EBER)-positive patients among 46 consecutive immunocompetent patients of SP and compared the clinicopathologic features of these patients with those of the EBER-negative cohort. In the 4 EBER-positive patients, the common presenting feature was a local mass lesion without symptoms of chronic active EBV infection. Upon histologic examination, neoplastic cells demonstrated well-differentiated morphology in the absence of plasmablastic lymphoma components. Fluorescence in situ hybridization analysis showed that all cases were negative for del13q14, t(11;14)(q13;32) and MYC rearrangement but that 1 case had cytogenetic aberrations involving del17p13. Follow-up data revealed that EBER-positive patients had benign prognoses without aggressive clinical course and that there was no significant difference in the overall survival time between the 2 groups, but EBER-positive patients were more likely to have disease progression (relapse/progression to multiple myeloma) compared with EBER-negative patients. More case studies are needed to better understand the impact of EBV on disease pathogenesis and development in immunocompetent patients of SP.

Recipient-derived EBV-positive Monomorphic Plasmacytoma Type Posttransplant Lymphoproliferative Disorder After Allogeneic Stem Cell Transplant for Severe Aplastic Anemia: A Case Report.

Monomorphic plasmacytoma-type posttransplant lymphoproliferative disorder (PTLD) has not been reported after pediatric hematopoietic stem cell transplantation. We present a child with hepatitis-associated severe aplastic anemia who underwent an unrelated allogeneic hematopoietic stem cell transplantation and subsequently developed graft failure and an Epstein-Barr virus-positive monomorphic plasmacytoma-type PTLD of recipient origin. Despite broad-spectrum antimicrobials, weaning immunosuppression, rituximab administration, and a stem cell boost she died from complications of PTLD and a fungal pulmonary infection on day +78.

Unusual coexistence of extramedullary plasmacytoma and nasopharyngeal carcinoma in nasopharynx.

Nasopharyngeal carcinoma (NPC) is an EBV-associated malignant tumor of nasopharynx. As extremely rare condition, the second primary cancer of nasopharynx can occur in NPC patients synchronously or subsequently. Extramedullary plasmacytoma (EMP) is a rare tumor and commonly originates in the head and neck region. However, there is no report to describe a collision tumor of NPC and EMP occurring in the same nasopharyngeal mass. We report here an unusual case of synchronous coexistence of NPC and EMP occurring in the nasopharynx of an old male patient. A 63-year-old male patient presented with a 3-month history of right-sided nasal obstruction and recently intermittent epistaxis without enlargement of cervical lymph nodes. The solitary mass of nasopharynx was found by radiological and nasopharyngeal examination. Histologically, the mass contained two separated portions and displayed typically histological features of NPC and EMP, respectively. In EMP portion, the tumor was composed of monomorphic plasmacytoid-appearing cells with immuno-positive to CD79a, CD138, CD38, MUM-1 and CD56, but lack immunoreactivity to pan-CK (AE1/AE3), CD20, CD21 and EBERs. In NPC portion, the tumor cells formed irregular-shaped islands with diffusely immuno-positive to pan-CK (AE1/AE3), EMA and EBERs, but lack expressions of lymphoplasmacytic markers. A diagnosis of simultaneous occurrence of EMP and NPC in nasopharynx was made. There was no evidence of tumor recurrence or metastasis 18-month follow-up after radiotherapy. To our knowledge, it may be the first case of coexistence of EMP and NPC synchronously. In addition, the histological differential diagnosis and relevant potential mechanism of this unusual collision tumor were also discussed.

Epstein-Barr virus-positive plasmacytoma in immunocompetent patients.

AIMS: Extramedullary plasmacytomas are often localized, clinically indolent neoplasms, and affected patients usually respond to radiation therapy or limited cycles of chemotherapy. In contrast, plasmablastic lymphomas are clinically aggressive neoplasms composed of immunoblastic or plasmablastic cells and associated with more mature plasma cells in some cases. Patients with plasmablastic lymphoma usually have a poor prognosis despite aggressive chemotherapy. Evidence of Epstein-Barr virus (EBV) infection is uncommon in plasmacytoma, but common in plasmablastic lymphoma, and is therefore helpful in differential diagnosis. The aim of this study is to describe four cases of plasmacytoma arising in immunocompetent individuals that were diffusely positive for Epstein-Barr virus-encoded small RNA as shown by in-situ hybridization. METHODS AND RESULTS: We describe the clinicopathological and immunophenotypic findings of four EBV-positive plasmacytomas arising in immunocompetent patients. These tumours were characterized by diffuse proliferation of mature-appearing plasma cells intermixed with a briskly reactive, CD8-positive, TIA-1-positive cytotoxic T-cell infiltrate. Long-term follow-up was available for all patients, and all were alive and free of disease at last follow-up (median 43.4 months). CONCLUSIONS: We suggest the term EBV-positive plasmacytoma in immunocompetent patients for these lesions. It is essential to distinguish these tumours from plasmablastic lymphoma, as the latter diagnosis is associated with a much poorer prognosis, and patients require much more aggressive therapy.

Plasmablastic extramedullary plasmacytoma associated with Epstein-Barr virus arising in an immunocompetent patient with multiple myeloma.

We encountered a case of plasmablastic extramedullary plasmacytoma with multiple myeloma. Histological findings revealed that the extramedullary plasmacytoma of this patient was of the plasmablastic type, which was positive for λ-stain and EBV-encoded RNA. In contrast, bone marrow aspiration demonstrated a common-type multiple myeloma, which was positive for λ-stain and negative for EBV-encoded RNA. This was a rare case of plasmablastic extramedullary plasmacytoma associated with Epstein-Barr virus arising in an immunocompetent patient with multiple myeloma.

Plasmacytoma-like post-transplant lymphoproliferative disorder, a rare subtype of monomorphic B-cell post-transplant lymphoproliferation, is associated with a favorable outcome in localized as well as in advanced disease: a prospective analysis of 8 cases.

Post-transplantation lymphoproliferative disorder (PTLD) with plasmacellular differentiation has been reported as a rare subtype of monomorphic B-cell post-transplant lympho-proliferation with histological and immunophenotypical features of plasmacytoma in the non-transplant population. Here we present clinical, laboratory and histopathological features, treatment and outcome of 8 patients from the German prospective PTLD registry. Clinically, extranodal manifestations were common while osteolytic lesions were rare and none of the patients had bone marrow involvement. Immunohistochemistry showed light chain restriction and expression of CD138 without CD20 expression in all samples. An association with Epstein-Barr virus was found in 3 out of 8 cases. We suggest that the Ann Arbor classification is most useful for this disease entity and report a generally good response to treatment including reduction of immuno-suppression, surgery and irradiation in localized disease and systemic chemotherapy analogous to plasmacell myeloma in advanced disease.

EBV-positive plasmacytoma of the submandibular gland--report of a rare case with molecular genetic characterization.

Plasmacytomas are differentiated plasma cell tumors that present as a mass lesion in osseous or extraosseous sites. Although the most common site for extramedullary plasmacytomas (EMP) is in the upper respiratory tract, plasmacytomas initially presenting as salivary gland masses are very uncommon. We describe a case of an EBV-positive plasmacytoma presenting as a 7.7 cm submandibular mass in an elderly immunocompetent man which displayed an abundance of "naked nuclei" on fine needle aspiration cytology. The tumor showed lambda light chain restriction and positive expression for CD38, MUM1 and EBER. Subsequent investigation for myeloma revealed absence of M-protein and end-organ damage, except for a lytic lesion in the radial bone. An extensive fluorescent in situ hybridization analysis showed the tumor to be negative for the t(4;14) FGFR3/IGH translocation as well as translocations involving the IGH, IGL, IGK, CCND1, BCL2, BCL6 and C-MYC genes. KRAS genetic analysis did not reveal any mutations of codons 12, 13 and 61.

Plasmablastic lymphomas with light chain restriction - plasmablastic extramedullary plasmacytomas?

BACKGROUND: It is diagnostically difficult to differentiate plasmablastic lymphomas (PBLs) from plasma cell neoplasms with plasmablastic differentiation. Plasmablastic lymphomas are currently classified as 'PBL of the oral mucosa' and 'PBL with plasmacytic differentiation'. METHODS: Forty-five cases of PBL were retrieved from the Departments of Oral Pathology of the Universities of Pretoria and Limpopo, South Africa. Clinical features and HIV status were recorded and each case was classified as 'PBL of the oral mucosa type' or as 'PBL with plasmacytic differentiation'. Immunohistochemistry included: CD45, CD3, CD20, CD79a, CD38, CD138, MUM1, Ki-67 and kappa and lambda light chains. Positivity was recorded based on the percentage of positive staining cells as focal (5-20%); intermediate (20-70%) or diffuse (>70%). In situ hybridization was performed for Epstein-Barr virus (EBV) and HHV-8. Results were recorded as positive or negative. RESULTS: All cases showed some degree of plasmacytic differentiation. All were negative for CD20 with reactive T cells detected with CD3. Diffuse and strong positive staining was found with Ki-67 and MUM1, but variable immunoreactivity was found with CD79a, CD45, CD38 and CD138. Twenty cases (47%) showed light chain restriction. Epstein-Barr virus was detected in 44/45 cases and HHV-8 in none. CONCLUSIONS: The morphological classification of PBLs is not valid as all cases showed some degree of plasmacytic differentiation. We propose that PBLs with light chain restriction be reclassified as 'plasmablastic extramedullary plasmacytomas' and managed accordingly. The rest represents true PBLs. The true nature of these neoplasms as an entity should be further investigated with molecular and genetic studies.

Primary cutaneous giant cell plasmacytoma in an organ transplant recipient: a rare presentation of a posttransplant lymphoproliferative disorder.

Posttransplant lymphoproliferative disorder (PTLD) is comprised of a spectrum of lymphoid diseases, ranging from early lesions, such as plasmacytic hyperplasia, to monomorphic neoplasms, including plasmacytoma-like lesions. Although PTLD may involve a variety of organs, primary cutaneous PTLD is rare. We report a unique case of Epstein-Barr virus (EBV)-positive primary cutaneous giant cell plasmacytoma developed 5 years after renal/pancreatic transplant in a 55-year-old male patient. The patient received local radiotherapy without reduction in immunosuppression and responded well. A review of the literature identified additional 49 cases of primary cutaneous B-cell PTLD, including 18 cases of plasmacytoma-like lesions. Primary cutaneous B-cell PTLD usually presents years after transplantation, has male preponderance, tends to occur on extremities, is frequently EBV-associated, and predicts a favorable clinical outcome. Unlike PTLD in general, in which EBV-positive cases usually occur earlier than EBV-negative ones, the longer presentation interval in the cutaneous PTLD seems to be uncorrelated to EBV status. Compared with other subtypes of cutaneous B-cell PTLD, plasmacytoma-like lesions have an increased male preponderance and tendency to present on the extremities. Although the majority of cases have been treated with reduction of immunosuppression, antiviral therapy and/or local radiotherapy, and a few with chemotherapy, the best therapeutic intervention for primary cutaneous B-cell PTLD remains to be further investigated with the analysis of more reported cases and large clinical trials.

Plasmablastic cytomorphologic features in plasma cell neoplasms in immunocompetent patients are significantly associated with EBV.

Multiple myeloma (MM) is rarely associated with Epstein-Barr virus (EBV) irrespective of HIV status, in contrast with its morphologic mimic, plasmablastic lymphoma, which occurs mainly in immunocompromised patients with frequent EBV association. Among 58 consecutive immunocompetent patients, we found plasmablastic cytomorphologic features in 2 of 4 with plasmacytomas and 14 (26%) of 54 with MM. Of the tumors, 4 (7%; 1 plasmacytoma and 3 MMs) were EBV-encoded RNA (EBER)-positive with plasmablastic cytomorphologic features in 3. The patient with plasmacytoma was disease free for 75 months, and the remaining 3 patients with MM died at 15, 74, and 97 months, respectively; the median survival of patients with EBER- MM was 12 months. EBV+ tumors were associated with plasmablastic cytomorphologic features and high labeling indices. Rare EBER+ plasmablastic plasma cell tumors exist in immunocompetent patients. These tumors may have been driven by EBV to gain the plasmablastic cytomorphologic features and high proliferation fraction. A large cohort study is needed to clarify the prognostic impact of EBV on immunocompetent patients with MM.